BS: Jump starting an engine

Subject: BS: Jump starting an engine
From: gnu
Date: 15 Feb 12 - 06:02 PM

Well... I don't know a lot about yer lectrickity. It's sneaky. Ya can't see it and it can mess ya up real bad. Fact is, other than rubbin a balloon on my hair (well, not any more) and stickin it on a wall er scuffin my socks on the carpet and touchin my bro's ear lobe, I really don't know a whole lot. Oh, I got the basics but I just don't trust myself to try "new things".

Soooo... if I jump start an engine by hookin a 12V source to a 6V battery feeding a starter... will I die? Is there even such a thing as a "12V source"? I mean, iffin they are both DC, does it matter? Can I jump start a 6V battery starter system with my truck?

Subject: RE: BS: Jump starting an engine
From: John MacKenzie
Date: 15 Feb 12 - 06:14 PM

Shouldn't do it really. I certainly wouldn't try it.

Subject: RE: BS: Jump starting an engine
From: Don(Wyziwyg)T
Date: 15 Feb 12 - 06:21 PM

Not likely to be dangerous to you gnu, but it will most likely knacker the six volt battery, and don't forget there's a chance of damaging the starter motor which is also designed for six volts.

Don T.

Subject: RE: BS: Jump starting an engine
From: Ed T
Date: 15 Feb 12 - 06:34 PM

I believe it could overcharge the 6 volt battery and kill it.

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 15 Feb 12 - 06:48 PM

Certainly makes sense but I gotta ask when I don't know. I'da never tried it without asking but I thought I'd try asking the question to see if I didn't know fer sure if it was a dumb idea or not. I think.

Thanks.

Subject: RE: BS: Jump starting an engine
From: Leadfingers
Date: 15 Feb 12 - 07:15 PM

If the engine is using 6 volt electrics , DONT use 12 volt ! You MAY get away with it , but you are more likely to cook the battery AND the starter motor

Subject: RE: BS: Jump starting an engine
From: Ed T
Date: 15 Feb 12 - 07:18 PM

This guy seems to say 12v can safely run a 6v starter?

12-6 volts

Subject: RE: BS: Jump starting an engine
From: Ed T
Date: 15 Feb 12 - 07:24 PM

Evidence that it may work with older vehicled here-but not sure if it would cause damage in a newer one?

12 volt

Subject: RE: BS: Jump starting an engine
From: Bobert
Date: 15 Feb 12 - 07:32 PM

If it's just a quick jump start then go for it... What it will do is make your starter motor turn twice as fast... Won't hurt either the 12V or 6V battery as long as both systems are negative ground... But do it fast... Don't think you'll just let the 12V system recharge the 6V battery... Get the engine started and then let the 6V generator/alternator do the rest...

B~

Subject: RE: BS: Jump starting an engine
From: GUEST,999
Date: 15 Feb 12 - 07:43 PM

Gnu, the following site is a good one about boosting in general. The order of attaching the cable clamps is important.

http://www.ag.ndsu.edu/pubs/ageng/safety/ae1021w.htm

Subject: RE: BS: Jump starting an engine
From: McGrath of Harlow
Date: 15 Feb 12 - 08:02 PM

Why risk it? Most times I've needed a jumpstart I've found that standing by the road holding up the jump cables seems to produce a helpful motorist before too long.

Or you can buy a jump starter you can stick in the boot for about £30. (For example)

One of the nuisances with modern cars is that "improved" technology means that a pushstart or a rolling start is no longer considered advisable.

Subject: RE: BS: Jump starting an engine
From: GUEST,999
Date: 15 Feb 12 - 08:05 PM

My questions: what make and model of vehicle and what year?

Subject: RE: BS: Jump starting an engine
From: Bobert
Date: 15 Feb 12 - 08:22 PM

Well, I used to be a certified Chevy mechanic and owned and operated a VW shop...

Believe me... It's okay... Just do it quick... Make sure both are negative ground or it will change the polarity and mess up your voltage regulator and generator/alternator...

B~

Subject: RE: BS: Jump starting an engine
From: Rapparee
Date: 15 Feb 12 - 08:34 PM

If your vehicle has a 6 volt system it's an old vehicle. If it's an oldie, is it a manual tranny? If it is, head it downhill and at about 6 mph pop the clutch (or get some friends to push it, assuming you have any friends) and the engine should start. Once it starts, don't stop it until the battery's charged.

If you have friends and they're pushing, you can help them a lot by having the car in neutral and the parking brake off. If you get a push from another vehicle AND the other guy's airbags don't go off be certain there's a gap of about 10 or 12 feet before you pop the clutch or Bad Things will happen to the pusher.

Subject: RE: BS: Jump starting an engine
From: catspaw49
Date: 15 Feb 12 - 08:54 PM

Don't tell anyone to push with an airbag equipped car........please.

Bobertz has it right and just make it quick. Running a 6volt ignition system and primary wiring on 12v is a no-no.

BTW......Batteries will explode. OCcasionally one that is severely discharged will not like it when hooked up for a jump and will be trying to recharge itself which produces hydrogen which goes boom when a spark is around.....like when you disconnect...........

Spaw

Subject: RE: BS: Jump starting an engine
From: Rapparee
Date: 15 Feb 12 - 09:16 PM

Ya know, you can actually call CAA or somebody....

I remember when airbags where first installed on cars. Like those of the Ohio State Patrol, who sometimes have to push a car out of a lane of traffic. Officers were less than pleased with the result, and modifications quickly followed.

You're damned right batteries will explode! When they do they can put a lot of sulfuric acid around as well as fragments. I saw it happen back when I was in the bloody Army. ERs don't like battery explosions and the patients like them even less. (This from a guy who used to sit in class on the fourth floor of the college and watch batteries and aerosol cans explode in the OPEN FIRE PIT down on the ground. Some of those explosions threw fragments higher than the five floors of the college building. This was, obviously, pre-EPA.)

Subject: RE: BS: Jump starting an engine
From: Greg B
Date: 15 Feb 12 - 09:21 PM

The thing to worry about is the ground. Generally, 6-volt systems are positive ground (earth) and 12 is negative.

(My credentials involve owning a 1956 International 300 Utility tractor, which I've not yet go 'round to converting to 12V positive ground).

So long as you isolate everything, the 12V shot of power can only give you a gain. Indeed, most 6 to 12 volt conversions don't bother to swap out the starter motor, as those old starters just do fine. When it finally does succumb, you just get the same shell from a few years later model designed for 12 volts.

The big deal with 6 volt systems is that the wire size needs to be ridiculously huge--- hard to come by now--- to handle the amperages involved in starting a tractor on a cold winter's day.

Not uncommon to see a very slow crank-over with a smoking solenoid.

I really do need to carry out that 12-volt negative ground conversion.

Subject: RE: BS: Jump starting an engine
From: kendall
Date: 15 Feb 12 - 09:22 PM

I've done this many times with no ill effects. But, as has been said, do it quickly.

Subject: RE: BS: Jump starting an engine
From: Bobert
Date: 15 Feb 12 - 09:25 PM

Don't listen to Kendall... He's a 7 Volter...

B;~)

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 15 Feb 12 - 09:38 PM

So.... here is THE deal... got a battery in a generator that won't hold a charge (Honda makes em that way... the charging system is designed so ya gotta run the genie for hours ta get a decent charge and stand-by genies just don't get that kinda use) and I wanna know if I can use a Crappy Tire 12V "PowerPak" ta boost it ta start the genie if my back gives out again, which it just might if I gotta use the pull start. Sounds like I shouldn't... sounds like I can.

I bought an intelligent battery charger at Crappy but the battery is on it's last legs.

Mind you, I don't even know if the genie battery is 6V or 12V. The manual doesn't say. Honda.ca don't neither. I could call the Honda surgeon but they are closed for the day. In any case, I am ejoying the discussion.

Subject: RE: BS: Jump starting an engine
From: Rapparee
Date: 15 Feb 12 - 10:53 PM

Honda Auto, M/C, P/E & Marine
    Customer Relations

    180 Honda Blvd.
    Markham, ON
    L6C 0H9

    Toll Free: 1-888-9-HONDA-9 (1-888-946-6329)
    Hours: 8:00 am to 7:30 pm Mon to Fri (EST)

You're looking for P/E, which is Power Equipment, not PEI. You might try calling the number above on the morrow.

Subject: RE: BS: Jump starting an engine
From: catspaw49
Date: 15 Feb 12 - 11:38 PM

They probably use batteries and have Honda equipment on PEI..........

Subject: RE: BS: Jump starting an engine
From: GUEST,999
Date: 16 Feb 12 - 12:20 AM

Electricity ain't made it to PEI yet. They're waiting out the Mayan calendar thing and December 21, 2012.

Subject: RE: BS: Jump starting an engine
From: GUEST
Date: 16 Feb 12 - 03:38 AM

You by cheap - you reap what you sow.

Expect to "pop " the diode in the alternator (generators live in "antiquity) .


Consider a quality GM or Chrysler product before purchaseing another "rice burning. They may cost more up front ... but you will save a world of aggravation down the. road.n

Subject: RE: BS: Jump starting an engine
From: GUEST,BobL
Date: 16 Feb 12 - 04:56 AM

You got two different possibilities here. If you try jumpering a 12v battery to a 6v one, I'd expect the 6v one to fry, PDQ. HOWEVER, if you (briefly) hook the 12v battery direct to the 6v starter motor, leaving the 6v battery to provide the spark, you may get away with it.

This needs you to access the contacts on the starter motor switch, not normally a problem under a car hood but may not be so easy in a jennie set.

Oh, incidentally the starter motor is probably not polarity sensitive. Just make sure that those different polarities don't ever get connected to each other...

Subject: RE: BS: Jump starting an engine
From: Mr Happy
Date: 16 Feb 12 - 06:15 AM

Shame no starting handles anymore!

Subject: RE: BS: Jump starting an engine
From: Ed T
Date: 16 Feb 12 - 07:27 AM

They got electricity in '58 where I lived on PEI as a boy. (that was 1958, not 1858)

Subject: RE: BS: Jump starting an engine
From: GUEST,olddude
Date: 16 Feb 12 - 10:52 AM

instead of going negative to negative, put the negative on the car frame. Far less chance of exploding ... Spaw is absolutely correct as usual, I never had one blow up but I sure knew people that did. Ain't good at all

Subject: RE: BS: Jump starting an engine
From: GUEST,Jon Dudley
Date: 16 Feb 12 - 01:07 PM

I've just done it! Jump started a 6v car with a 12v battery that is. Having asked all manner of wise people I took a chance. The general consensus seems to be that providing you turn all ancillaries off on the 'dead' 6v vehicle and providing you don't make habit of it, it's ok. I used a 12 volt car to start my 6v Citroen 'Traction' and blimey the starter motor didn't half spin!

Subject: RE: BS: Jump starting an engine
From: Rapparee
Date: 16 Feb 12 - 01:22 PM

I still think you ought to get some people to help you push-start it.

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 16 Feb 12 - 01:42 PM

I had a 1974 Runsonlydownhill that I push started by myself for about 6 months. But, that just ain't practical come winter. Of course, when other people were getting a ride, they did the pushing.

Subject: RE: BS: Jump starting an engine
From: JohnInKansas
Date: 16 Feb 12 - 02:38 PM

gnu says "can't tell" if the generator battery is 6V or 12V.

A lead-acid cell is "about 2 volts" so a 6 volt battery has 3 "cells" in series inside the box and a 12 volt battery has 6 cells. It's rare to see a battery that doesn't have a cap, or on a very few of them a "view window" for checking the amount of water in each cell, one cap/window for each cell. On 12V batteries it's common to find two rectangular "stoppers" with three "plugs" on each one, so that when you pull each of the two rectangular blocks off it shows you three holes. You can nearly always tell how many cells are in one, and once you count them you know whether it's 6V or 12V.

You can also just use a voltmeter, since a battery is "effectively dead" at about 70 - 80% of its nominal voltage, and will still tell you what it is.

About the only exception is for the specialized "leakproof" batteries used in electric contraptions for the handicapped, such as "mobility scooters" or "electric wheelchairs," where the batteries are completely sealed and have no holes to look at. Very few of these use the normal "bolt" or "clamp" connections for the cables, and most of them have only a couple of little "tin ears" sticking out of either the top or the side. Batteries of this "odd" type are almost exclusively used with two in series and requiring a 24V charger.

Even the supposedly "spillproof" motorcycle batteries, which sometimes are 6V, still have the caps on them, unless they've been "specially equipped" for competitive motcross competition where sometimes the rules require the true "leakproof" ones.

Of course the safer method would be to go to Honda Power Equipment Owner's Manuals where it says you can download (pdf) a free manual, or order (for a price) a printed paper copy. The down side of this is
you do have to RTFM
once you get it. (Note that you may have to give them the the model number for your generator, and for some models you may also need a serial in order to get the right downloads. At the Honda site they'll show you where to look to find both if you need them both. They also offer "shop manuals" that probably have a lot more info, but I didn't look at whether those are also free downloads.)

John

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 16 Feb 12 - 03:17 PM

TFM specs don't say.

"... where the batteries are completely sealed and have no holes to look at." Well, there ya go eh.

A call to the Honda surgeon has confirmed it is a 12V. So, I can jump start it with a power pak if my back has an attack.

Subject: RE: BS: Jump starting an engine
From: EBarnacle
Date: 16 Feb 12 - 03:32 PM

With the Citroen, why didn't you just use the built in crank?

Subject: RE: BS: Jump starting an engine
From: GUEST,olddude
Date: 16 Feb 12 - 04:16 PM

We can strap my gus gus dog to the bumper, that 130 lb beast could pull a tractor out of the mud

Subject: RE: BS: Jump starting an engine
From: kendall
Date: 16 Feb 12 - 04:32 PM

My generator has a Briggs & Stratton engine with no battery or starter. One pull on the rope and it is running.

Subject: RE: BS: Jump starting an engine
From: JohnInKansas
Date: 16 Feb 12 - 06:41 PM

Most lead-acid batteries will have a "Cold Current Cranking Amperage" usually but not always marked on the outside as "CCA." This is (approximately) the maximum current you can get out of the battery when the battery is fully charged and it's connected to a "standard resistance" that's usually sort of an approximation to a starter motor. The limiting factors that determine the CCA rating of the battery are mostly related to the effective resistance of all the connections inside and between the battery cells.

Although it's meant to indicate how fast you can "take out" of the battery, the CCA rating is a reasonably good indicator of the maximum current you can put into the battery to charge it, although the numbers may not be exactly the same.

Batteries also have a "capacity" expressed in Ampere Hours and sometimes molded into the housing as an "AH" rating. That's the product of the current you drain out of it multiplied by the time it will keep coming. "Flipped around," the AH capacity also tells you how long it will take to charge the battery from "dead" - or very low - to full charge, at a current approximating something in about the same range as the CCA rating.

Most battery chargers apply a voltage around twice the voltage rating of the battery when you first hook them up, but include a current limiter so that the charging current doesn't exceed the rating of the charger. As the battery voltage comes up, the "regulator" in the charger should taper off the charging rate so that the "last few hours" are at a comparitively miniscule current.

If you divide the AH rating (all the juice the battery can hold) by the CCA rating (the maximum current you can force into it at reasonable voltage) you get approximately the minimum time it will take to charge the battery. Since the charger should taper off the rate as the battery starts to fill up, you usually can figure about twice what the simple calculation gives you.

Since most chargers have a current rating much lower than the likely CCA rating of the battery, you need to divide the AH rating by the rated current of the charger to get a reasonable time to charge from that charger - and then multiply by about 2 (or more) since the charging rate should taper off as the battery charges.

A fairly typical auto battery that happens to be out on my shelf has an AH rating or 785 ampere-hours and a CCA rating of 140 amps. From "dead," it would be risky to try to charge that battery in less than 785/140 = 5.6 hours. Actually, since a current that high all the way up to full charge would likely produce a whole lot of hydrogen and very probably an explosion, I'd figure a little more than twice that, or maybe 12 - 15 hours to get to a "nominally full charge." But since my biggest handy charger has a very typical 10 amp capacity, in practice I'd expect about a week to fully charge that one from the charger, if I started from a really "dead" condition.

Fortunately, you don't really need to "fully charge" a battery, and most charging systems, as on your auto, NEVER get very close to the theoretical "fully charged" condition. If a "dead" battery still clicks the solenoid, and sometimes if it only makes a click when you switch the radio on/off, it's still "part way there" so with a reasonably adequate charger a half hour or so usually will bring the battery up enough to start most typical engines. The charging system on the vehicle, once the engine runs, is usually a better way to finish bringing the battery up than even a good charger; although as indicated (sort of) above, you can burn a lot of fuel for a limited benefit if all you're doing is charging the battery. Small generators and mowers may have exceedingly "primitive" charging systems, so you need to study what you've got (preferably by observation of how it behaves) to get a good estimate of how well it "maintains."

When you connect a "dead" battery to a "fresh" battery, the CCA rating of the good one tells you the maximum rate you can expect current to come out of the good one, and the CCA rating of the dead battery will tell you approximately the maximum current you can put into the dead one (with "battery voltage" differences between the two). If you divide the AH rating of the dead battery by the CCA rating of the dead battery, you get a very approximate number of hours you can put current in without getting the dead battery up to full charge. A battery only generates significant amounts of hydrogen when it's "receiving current" and when it's near full charge, so as long as you don't leave a 12V battery connected to a 6V battery longer than the time calculated for the (dead) 6V one, you're unlikely to get much explosive danger. Additionally, once you "hit the starter" it's likely that most of the current that the good battery can supply will go to the lower resistance of the motor, rather than into the dead battery.

The theoretical time it should take to bring the dead battery up to near full charge can give you some idea of how long it's safe to have the two batteries connected for a jump start. Most of the peripheral factors that you'd need to include for a really accurate calculation are "in your favor" which makes the time caluclated as indicated significantly "conservative." With nearly all combinations, it is considered "safe" to jump a 6V vehicle from a 12V one; but it's recommended that you be very conservative about leaving the hookup together if you don't get a quick start, and you should disconnect the jumpers as soon as possible. Left connected for too long, the 6V battery will always start releasing explosive gases after a fairly short time that can cause a "really bad day event."

John

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 16 Feb 12 - 07:02 PM

Yes, Kendall, but does it have an Eco-throttle to conserve fuel consumption? When this puppy is only powering a few lights it uses very little fuel and it ramps up automatically to match the load, powering the furnace (or AC), fridge, freezer, TV, microwave... when it needs to. It can go 5.1 hours at full tilt on a tank of gas (16.5l) and 14 hours at low throttle which means 8 hours of sleep for me when the power is out. It eases Mum's mind... and, therefore, mine.

Me? I have a Norwegian style stove that comes apart for transport. Dangerous as hell but it'll keep the pipes from freezing. And I have a lot of blankets and a badass sleeping bag. No generator.

Subject: RE: BS: Jump starting an engine
From: kendall
Date: 16 Feb 12 - 07:30 PM

Don't know. Never had to run it for more than a few minutes.

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 16 Feb 12 - 07:46 PM

That's a good thing.

Subject: RE: BS: Jump starting an engine
From: GUEST,Jon Dudley
Date: 16 Feb 12 - 07:56 PM

In answer to Mr (or Mrs) Barnacle...unfortunately the Citroen's starting handle is missing and the bracketry is useless. Hence the jump start. The Traction usually 'commences' on 6v but it always sounds like a struggle.

Subject: RE: BS: Jump starting an engine
From: Bobert
Date: 16 Feb 12 - 07:58 PM

Listen, gn-ze... You got Tractor Supply up there??? If so, you can buy a new battery for $79 out the door... Put it in the car and quit with all these jirations...

Geeze...

B~

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 16 Feb 12 - 08:23 PM

"Geeze"? Huh? It ain't a car. I can get a car battery for less than $79. But... it ain't a car. It's a Honda generator and there ain't no battery that I can find elsewhere that would fit in the space and I wouldn't wanna on accounta the charging system only works if yer runnin the generator for HOURS at a time. I run it ten to twenty minutes a week just to test it and use up gas so the gas doesn't go stale. I keep an intelligent charger on it but it has run down so much that it has a hard time when it's -20C.

Subject: RE: BS: Jump starting an engine
From: Bobert
Date: 16 Feb 12 - 08:54 PM

Well, gol danged... Pull the sumabich out and take it to Tractor Supply... They'll match it up...

No, wait!!! Just leave the generator running and it will keep the battery charged...

B;~)

Subject: RE: BS: Jump starting an engine
From: Rapparee
Date: 16 Feb 12 - 09:07 PM

AND you'll save on your electric bills!

Subject: RE: BS: Jump starting an engine
From: Bobert
Date: 16 Feb 12 - 09:38 PM

You ain't dealing with mo ordinary hillbillies here, gn-ze... Me and Rap know what we're talkin' about here...

B~

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 16 Feb 12 - 10:26 PM

Yas ain't no more hillbillies what I am a good ol boy.

Subject: RE: BS: Jump starting an engine
From: JohnInKansas
Date: 17 Feb 12 - 12:42 AM

Where "cold starts" are a real problem, a common method is a small (for portability) battery kept on a "maintenance charger" in the garage, or where possible in another appropriate semi-heated area. You can then carry the warm charged battery to the device that needs a boost, and clip it onto the regular battery to get enough kick for an easy start.

Lugging a normal auto battery out from the barn is about as much hard labor as yanking a starter rope, but you probably don't need anything that large for what's been described.

For a generator of about the size suggested by your description you quite likely could use a motorcycle battery for the kicker, and the amount of boost needed wouldn't require more than AWG10 or 12 lead wires and small clips, so you don't have to fight with the #6 wires and battery clamps on a real set of jumper cables.

A good cycle battery probably will run close to $50 at common outlets at today's prices, and a pretty good maintenance (motorcycle) charger may be close to $20, but they should be easy to find, even if you have to go to WallyWart. A couple of years ago you might have found both for under $50 (US) at the same places.

An alternative might be to just hang a small (1 or 2 Amp) "keeper" charger on the frame of the generator and run a "permanent" extension cord to it. Lots of people use chargers of that kind to keep their motorcycle batteries up in the "off season" if they're "seasonal wussies" and don't ride them over the winter. Typical ones are about the size of 4 decks of poker cards, or even a little smaller.

John

Subject: RE: BS: Jump starting an engine
From: Greg B
Date: 17 Feb 12 - 09:31 AM

My tractor has both an electric "battery blanket" to keep it warm in below-freezing temps and a nice electronic "trickle charger" to keep the battery peaked up.

I have a kit that will convert it to 12V negative earth and an alternator, but am missing the round tuit.

Subject: RE: BS: Jump starting an engine
From: gnu
Date: 17 Feb 12 - 01:29 PM

As above, my intelligent charger is hooked up at present. And, I have a power box for jumping (I have 5 for two houses during short power outages... the first thing connected is my computer so I can find out the expected duration of the outage and decide to use the boxes or fire up the gennie).